Folding Electric Apparatus

1. A folding electronic apparatus in which a first housing and a second housing are connected to each other by a hinge having an axis and are capable of being opened and closed with respect to each other by rotation about the hinge axis, the hinge including: a pipe portion having a first slit on a side wall, the pipe portion being attached to one of the first housing and the second housing; and a hollow shaft having a second slit on the side wall, the hollow shaft being attached to the other of the first housing and the second housing, the hollow shaft being engaged inside the pipe portion, wherein the first and second slits extend to positions shifted from an engaging portion of the pipe portion with the hollow shaft in the axial direction and define opening portions of the first and second slits.

2. A folding electronic apparatus according to claim 1 , wherein the first slit provided on the side wall of the pipe portion extends in the axial direction, the second slit provided on the side wall of the hollow shaft also extends in the axial direction, and when the first and second housings are located at a predetermined angular position about the hinge axis, the first and second slits are aligned and continuous with each other in the axial direction.

3. A folding electronic apparatus according to claim 1 , further comprising: a first printed circuit board attached inside one of the housings; a second printed circuit board attached inside the other of the housings; and signal wires electrically connecting the first printed circuit board with the second printed circuit board, wherein one end portion of the signal wires connects to the first printed circuit board, enters the first slit opening portion of the pipe portion, passes inside the pipe portion and the hollow shaft portion, comes out from the second slit opening portion of the hollow shaft portion and connects to the second printed circuit board.

4. A folding electronic apparatus according to claim 3 , wherein the signal wires are formed into a flexible printed circuit.

5. A folding electronic apparatus according to claim 4 , the flexible circuit plate including: a first base portion connected to the first printed circuit board; a first portion extended from the first base portion in the direction perpendicular to the hinge axis; a portion bent from the first portion in the direction parallel with the hinge axis; a second portion bent from a portion which extends in the direction parallel with the hinge axis, extending again in the direction perpendicular to the hinge axis; and the second base portion connected to the second portion and connected to the second printed circuit board, wherein the flexible circuit plate is formed into a plane shape.

6. A folding electronic apparatus according to claim 5 , wherein the plane shape of the flexible printed circuit is folded in two.

7. A folding electronic apparatus according to claim 5 , wherein the portion of the flexible printed circuit, which is parallel with the hinge axis, passes inside the pipe portion and the hollow shaft portion.

8. A folding electronic apparatus according to claim 1 , wherein an end portion of the hollow shaft in the axial direction on the side opposite to the side engaged with the pipe portion is closed with a wall, an end portion of the pipe portion in the axial direction on the side opposite to the side engaged with the hollow shaft is closed with a wall, and a space portion for accommodating the flexible printed circuit is defined by the inside of the pipe portion and the inside of the hollow shaft and by the respective walls closing the corresponding end portions of the pipe portion and the hollow shaft portion.

9. A folding electronic apparatus according to claim 1 , the pipe portion including: a pipe formed portion integrally formed on the first chassis, a structural reinforcing member comprising one of the housings; and a pipe member engaged inside the pipe formed portion, wherein slit portions are respectively formed in the pipe formed portion and the pipe member at positions corresponding to each other, and are aligned with each other to form the first slit.

10. A folding electronic apparatus according to claim 9 , wherein the pipe member is formed of resin, the pipe member has rising walls on both sides of the slit, the first chassis is integrally formed of magnesium by means of die casting, and when the rising walls on both sides of the pipe member are engaged with the slit of the pipe formed portion, the pipe member is engaged non-rotatably with the pipe formed portion of the first chassis.

11. A folding electronic apparatus according to claim 1 , wherein the other of the housings has a second chassis which is a structural reinforcing member, integrally formed of magnesium by means of die casting, and the hollow shaft has a flange portion fixed to the second chassis by means of screwing.

12. A folding electronic apparatus according to claim 1 , wherein the hollow shaft has a protrusion or a step, which regulates a position of the hollow shaft in the axial direction when the hollow shaft is pivotally engaged with the pipe portion, on the outer circumference thereof.

13. A folding electronic apparatus according to claim 1 , wherein both sides of the pipe portion of one of the housings are open, the hollow shaft is engaged with the first opening portion, and a hinge module is inserted into the second opening portion and the bearing portion of the other of the housings.

14. A folding electronic apparatus according to claim 13 , wherein the other of the housings has a second chassis which is a structural reinforcing member, integrally formed of magnesium by means of die casting, the bearing portion of the other of the housings is formed as a portion of the second chassis and, further, the second chassis has a semi-cylindrical portion to cover the hollow shaft.

15. A folding electronic apparatus according to claim 13 , wherein the hinge module is engaged with the second opening portion of the pipe portion of one of the housings and the bearing portion of the other of the housings, and regulates a rotary position between the first housing and the second housing.

16. A folding electronic apparatus according to claim 1 , wherein the folding electronic apparatus is a folding mobile phone.

17. A folding electronic apparatus in which a first housing and a second housing are connected to each other by a hinge being capable of being opened and closed, the hinge including: a pipe portion integrally formed with a structural reinforcing member of the first housing; a bearing portion integrally formed with a structural reinforcing member of the second housing; and a hollow shaft fixed to the structural reinforcing member of the second housing, wherein the hollow shaft is pivotally inserted into and engaged with one of the opening portions of the pipe portion, and a hinge module penetrates the other side of the pipe portion and the bearing portion.

18. A folding electronic apparatus according to claim 17 , wherein the first slit is provided on the side wall of the pipe portion, the second slit is provided on the side wall of the hollow shaft, and the first and the second slits extend to a position shifted in the axial direction from the engaging portion of the pipe portion with the hollow shaft portion and define the first and the second slit opening portions.